Driver assistance devices for automatically driving a motor vehicle are already known from the prior art. Therein, it is basically differentiated between fully automatic driver assistance devices on the one hand and semi-automatic driver assistance devices on the other hand. Semi-automatic driver assistance devices only assume the transverse guidance of the motor vehicle by automatically controlling the steering angle of the motor vehicle by means of the driver assistance device. In contrast, fully automatic driver assistance devices additionally control the drive train of the motor vehicle and thus also assume the longitudinal guidance of the motor vehicle, i.e. the acceleration and the deceleration. Presently, the interest is directed to an at least semi-autonomous driver assistance device, which outputs control signals at least to a steering device of the motor vehicle in the automatic drive mode in order to automatically control the steering angle. The driver assistance device can also be a fully automatic device, which additionally outputs corresponding control signals to a drive train of the motor vehicle. Therefore, the term “autonomous” can presently include both “semi-autonomous” and “fully automatic”.
In this context, for example, automatic parking assistance systems are known, which assist the driver in parking the motor vehicle. These driver assistance systems usually calculate a parking trajectory, along which the motor vehicle can be parked into a previously detected parking space without collision. The driver assistance device then autonomously controls the motor vehicle into the parking space according to the pre-calculated parking trajectory. In addition, systems are also known, which serve for automatically driving the motor vehicle in preset road situations or driving situations. For example, it is already prior art to automatically drive a motor vehicle in a congestion or else in a so-called convoy travel.
Such driver assistance devices overall pursue a common aim of providing the possibility to the driver of the automobile of relaxing during travel and for example using diverse multimedia systems. Therein, the driver himself can also assume the control over his vehicle anytime, as it is for example described in the documents US 2010/0228417, DE 10 2011 013 023 A1 as well as US 2012 089 294. These printed matters propose various methods, how the driver can again assume the control over his vehicle. Usually, therein, only the steering wheel has to be operated by the driver.
If a motor vehicle is automatically driven by means of a driver assistance device, thus, it is required in certain events to pass the control over the vehicle again to the driver. This is for example required if a risk of collision is detected or else if the environmental conditions fast change and for example rain is detected. However, the communication between the driver assistance device and the driver has proven problematic in such situations. If the control over the vehicle is again to be passed to the driver, this is to be correspondingly signaled to the driver, namely such that the driver is able to particularly fast and reliably conceive or appreciate the intent of the driver assistance device to surrender the control over the motor vehicle. This has proven difficult in the prior art in particular for the reason that the driver usually does not focus on the current road situation during automatic drive of the motor vehicle, but for instance on infotainment systems and the like. Thus, a particular challenge is in being able to direct the attention of the driver again to assumption of the control over his vehicle.
From the printed matter US 2011/0163863 A1, a device is known, which detects whether or not the steering wheel of the motor vehicle is operated by the driver. If operation of the steering wheel by the driver is not detected during movement of the motor vehicle, thus, alarm signals are output.
A driver assistance device for automatically driving a motor vehicle is known from the printed matter DE 10 2011 112 577 A1. Therein, by means of a lighting device, the direction is indicated, in which the motor vehicle moves in the current automatic drive maneuver.